Search results for " Reverse"

Desalination of oilfield produced waters via reverse electrodialysis: A techno-economical assessment

2023

Produced waters (PWs) are oilfield waste streams rich in minerals and hydrocarbons whose production rate is largely increased in last decades following the corresponding increase of energy demand. The high salinity level of PWs inhibits the adoption of cheap biological treatments. Also, desalination techniques based on osmotic membranes would require severe pre-treatments. As an alternative, Reverse ElectroDialysis (RED) and Assisted Reverse ElectroDialysis (ARED) are here proposed for the first time to reduce the salinity level of PWs. RED may also guarantee an operation cost reduction thanks to its energy generation. An ad-hoc model for RED and ARED is here developed in order to deal suit…

Sensitive determination of parabens in human urine and serum using methacrylate monoliths and reversed-phase capillary liquid chromatography-mass spe…

2014

A method for the determination of parabens in human urine and serum by capillary liquid chromatography (cLC) with UV-Vis and mass spectrometry (MS) detection using methacrylate ester-based monolithic columns has been developed. The influence of composition of polymerization mixture was studied. The optimum monolith was obtained with butyl methacrylate monomer at 60/40% (wt/wt) butyl methacrylate/ethylene dimethacrylate ratio and 50wt% porogens (composed of 36wt% of 1,4-butanediol, 54wt% 1-propanol and 10wt% water). Baseline resolution of analytes was achieved through a mobile phase of acetonitrile/water in gradient elution mode. Additionally, dispersive liquid-liquid microextraction (DLLME)…

Sodium bis(2-ethylhexyl)sulfosuccinate self-aggregation in vacuo: molecular dynamics simulation.

2010

Molecular dynamics (MD) simulations were conducted for systems in vacuo consisting of n AOT(-) anions (bis(2-ethylhexyl)sulfosuccinate ions) and n+/- 1 or n Na(+) ions up to n = 20. For n = 15, positively charged systems with Li(+), K(+), and Cs(+) cations were also considered. All systems were observed to form reverse micelle-like aggregates whose centre is occupied by cations and polar heads in a very compact solid-like way, while globally the aggregate has the form of an elongated and rather flat ellipsoid. Various types of statistical analyses were carried out on the systems to enlighten structural and dynamical properties including gyration radius, atomic pair correlation functions, at…

Twenty Years of HIV-1 Non-Nucleoside Reverse Transcriptase Inhibitors: Time to Reevaluate their Toxicity

2011

Twenty years of effective clinical application have consolidated non-nucleoside reverse transcriptase inhibitors (NNRTI) as essential components of the Highly Active Antiretroviral Therapy (HAART) employed in the treatment of Human Immunodeficiency Virus (HIV). However, as the disease has come under control, there has been growing emphasis on the long-term adverse effects induced by this chronic pharmacological therapy. Although traditionally considered to be safe and well-tolerated drugs, there is mounting evidence that associates NNRTI with the onset of cutaneous reactions, neuropsychiatric symptoms, hepatotoxicity, metabolic disturbances and gastrointestinal toxicity. Though the clinical…

Future Perspectives in NNRTI-Based Therapy: Bases for Understanding Their Toxicity

2011

Continuous administration of the drugs included under the term Highly Active Antiretroviral Therapy (HAART) has turned AIDS into a chronic disease, at least in developed countries (Panos et al., 2008). The initial development of these drugs was particularly rapid and focused on clinical efficacy before all other considerations. However, as the disease has come under control, there has been growing emphasis on the long-term adverse effects associated with this therapy. The first drug for the treatment of HIV infection, zidovudine (AZT), was approved in 1987. The number of other antiretroviral drugs already approved for use or under development continues to grow, and the primary aim of resear…

Assisted reverse electrodialysis for CO2 electrochemical conversion and treatment of wastewater: A new approach towards more eco-friendly processes u…

2020

Abstract In this paper, the utilization of assisted reverse electrodialysis (A-RED), recently used for pre-desalination, is proposed as a general method to reduce the energy requirements of electrolysis processes and evaluated for two model processes: (i) the cathodic conversion of carbon dioxide to formic acid; (ii) the anodic treatment of water contaminated by organics. In A-RED, two solutions with different salt content and an external potential difference, applied in the direction of the natural salinity gradient, are both used to drive redox processes. It was shown, for the first time, that the cathodic conversion of CO2 to formic acid can be performed by both reverse electrodialysis (…

Integrated three-dimensional models for noninvasive monitoring and valorization of the Morgantina silver treasure (Sicily)

2016

The Morgantina silver treasure belonging to the Archaeological Museum of Aidone (Sicily) was involved in a three-dimensional (3-D) survey and diagnostics campaign for monitoring the collection over time in anticipation of their temporary transfer to the Metropolitan Museum of Art in New York for a period of 4 years. Using a multidisciplinary approach, a scientific and methodological protocol based on noninvasive techniques to achieve a complete and integrated knowledge of the precious items and their conservation state, as well as to increase their valorization, has been developed. All acquired data, i.e., 3-D models, ultraviolet fluorescence, x-ray images, and chemical information, will be…

A simulation tool for analysis and design of reverse electrodialysis using concentrated brines

2015

Abstract Reverse electrodialysis (SGP-RE or RED) represents a viable technology for the conversion of the salinity gradient power into electric power. A comprehensive model is proposed for the RED process using sea or brackish water and concentrated brine as feed solutions. The goals were (i) reliably describing the physical phenomena involved in the process and (ii) providing information for optimal equipment design. For such purposes, the model has been developed at two different scales of description: a lower scale for the repeating unit of the system (cell pair), and a higher scale for the entire equipment (stack). The model was implemented in a process simulator, validated against orig…

self-assembly and intra-cluster reaction of erbium and ytterbium bis(2-ethylhexyl)sulfosuccinate reverse micelle in gas phase

2014

Exergy analysis of reverse electrodialysis

2018

Abstract Reverse electrodialysis in closed loop configurations is a promising membrane technology in the energy conversion and storage fields. One of the main advantages of closed-loop reverse electrodialysis is the possibility of using a wide range of operating concentrations, flow rates and different salts for generating the salinity gradient. In this work, an original exergy analysis of the reverse electrodialysis process was carried out in order to investigate reverse electrodialysis performance in terms of energetic and exergetic efficiency parameters in a wide range of operating conditions. A mono-dimensional model of the reverse electrodialysis process was developed, in which all sou…